He will soon celebrate the 25th anniversary of a very important date — Dec. 24, 1990, at around 5 p.m.

It’s not his birthday — or his wedding anniversary. It’s the exact moment Ketchian said he realized he was happy.

“I found it. I felt it. didn’t want to let go of it,” Ketchian said.

Who doesn’t want to get — and stay happy?

Psychiatrist John Tamerin says for many people the root of everything we’re chasing, a better job, more money or true love, is happiness.

But this endless pursuit often backfires.

“If you lead your life always waiting for a great thing to happen, you probably will be unhappy,” Tamerin said.

Now, after decades of research and a dozen clinical trials, researchers at the world-renowned Mayo Clinic, say they’ve actually cracked the code to being happy, and published it in a handbook.

Dr. Amit Sood led the research and says the first and foremost way to be happy is to focus our attention.

“You can choose to live focusing on what is not right in your life,” Dr. Sood said.

Experts say the human mind is instinctively restless, wandering from good thoughts to sad thoughts, scary thoughts and everything in between.

But if we learn to command our thoughts, shifting perspective away from the negative, and embrace the positive, we will be happier, experts say.

“Resiliency has everything to do with happiness,” Dr. Sood said.

The Mayo Clinic’s research also shows the degree of happiness people enjoy has to do with how resilient they are to life’s many curve balls. Happy people are very good at compartmentalizing and creating boundaries.

“So for example, if you’ve had a difficult day, when you get back home, for the first three minutes, forget about it, park it, and meet your family as if they’re long lost friends,” Dr. Sood added.

And perhaps one of the biggest hindrances to being happy is too much thinking about one’s self, research shows.

“Complainers are never going to be happy,” Ketchian said. “Happiness is a decision.”

So why did the Mayo Clinic decide to study happiness? Studies show happier people are healthier people.